The comedian, whose popular – and quotable – show about a quartet of narcissistic New Yorkers wrapped in 1998 after a nine-year run, gave away a few details about the project while appearing on a sports radio talk show Thursday, according to CBS New York.

Seinfeld, 59, was chatting about football on WFAN's Boomer and Carton when the hosts couldn't resist inquiring about the tantalizing photo that was taken of Seinfeld and Jason Alexander walking into Tom's Diner on Manhattan's Upper West Side (just as they had done so many times on the show).

Seinfeld confirmed the duo weren't filming a commercial or an episode of "Comedians in Cars Getting Coffee" (his hit web series), and once again referred to it as a "secret project."

"I gave you more now than I’ve given anyone," Seinfeld told the still-baffled hosts. "I told you what it isn’t. And then I also told you that it isn’t not that, either."

Not surprisingly, the hosts were unsatisfied with that response – and grilled the star for further details.

He obliged (kind of), confirming a few nuggets, including that Alexander reprised his role as neurotic George Constanza while they filmed in the diner, that the project involves original co-creator Larry David and that more of the show's characters are also involved.

Seinfeld called it a "short-ish"-form project, but that it's longer than 60 seconds and will go public "very very soon."

Only don't get too excited, super fans: Seinfeld says the project is probably "one and done."